Aplicación de las normas argentinas e internacionales en el análisis crediticio de una empresa siderúrgica. El caso de la empresa Tenaris S.A.

1- Introducción - 2- Metodología - 3- Resultado y Discusión - 3.1- Evolución de las Normas contables locales e internacionales y su aplicación en Argentina. Análisis de Estados Financieros para toma de decisión en las Entidades Financieras respecto del otorgamiento de créditos. - 3.2- Estudio descriptivo de la empresa Tenaris S.A. - 3.3- Confección de ratios y análisis de Informes Financieros al 31/12/14 y 31/12/13 con NIIF en base a las variables definidas: situación Financiera, Económica y Patrimonial - 3.4- Análisis de ratios e indicadores confeccionados en base a NIFF y las diferencias esperables siguiendo las normas locales, para detectar similitudes y diferencias en los criterios de decisión respecto al otorgamiento de créditos - 4- Conclusiones - 5- Bibliografía - AnexoEl presente trabajo final pretende responder a la siguiente pregunta: la aplicación de los distintos cuerpos normativos ¿tiene impacto en la decisión de otorgamiento de créditos? La contabilidad financiera surge para satisfacer las necesidades de información destinada a usuarios externos. Para que la información sea comparable se definen normas de registro. Entre ellas se distinguen dos cuerpos normativos, las normas locales y las internacionales. Ambas normativas son aplicables en nuestro país. De acuerdo con las RT 26 y 29 algunas firmas están obligadas a presentar información contable en base a normas internacionales. Sin embargo a los fines impositivos deben adaptar la información a normas locales o bien realizar los ajustes pertinentes y reflejarlos en notas. Hay numerosas diferencias entre ambos cuerpos normativos en cuanto a exposición, reconocimiento y criterios de medición. Esto hace que surjan incógnitas en cuanto a si la confección de estados financieros en base a normas diferentes hace que la información difiera. Las Entidades Financieras son uno de los usuarios externos de la información. Los bancos utilizan la información de los clientes para cumplir con normativas del órgano contralor (Banco Central de la República Argentina) y para analizar su aptitud crediticia. A fin de contestar la incógnita planteada en el primer párrafo, se considera el caso particular de la empresa Tenaris S.A., empresa industrial con cobertura global. Se desarrollarán a lo largo del trabajo las potenciales diferencias en la información contable en base a ambas normas. Se analizará la información financiera de Tenaris S.A. confeccionada en base a Normas Internacionales. Se estimarán en este caso en particular las potenciales diferencias en caso de usar normas locales. Se definirá si estas diferencias modificarían la aptitud crediticia de la firma. Finalmente se realizarán inferencias generales que se podrán aplicar a distintas situaciones.Fil: Serra, Cecilia Edit. Universidad Nacional de Córdoba. Facultad de Ciencias Económicas; Argentina

In Situ Raman Characterization of SOFC Materials in Operational Conditions: A Doped Ceria Study

[EN] The particular operational conditions of electrochemical cells make the simultaneous characterization of both structural and transport properties challenging. The rapidity and flexibility of the acquisition of Raman spectra places this technique as a good candidate to measure operating properties and changes. Raman spectroscopy has been applied to well-known lanthanide ceria materials and the structural dependence on the dopant has been extracted. The evolution of Pr-doped ceria with temperature has been recorded by means of a commercial cell showing a clear increment in oxygen vacancies concentration. To elucidate the changes undergone by the electrolyte or membrane material in cell operation, the detailed construction of a homemade Raman cell is reported. The cell can be electrified, sealed and different gases can be fed into the cell chambers, so that the material behavior in the reaction surface and species evolved can be tracked. The results show that the Raman technique is a feasible and rather simple experimental option for operating characterization of solid-state electrochemical cell materials, although the treatment of the extracted data is not straightforward.This research was funded by the Spanish Government (IJCI-2017-34110, RTI2018-102161 and SEV-2016-0683 grants).Solís, C.; Balaguer Ramirez, M.; Serra Alfaro, JM. (2020). In Situ Raman Characterization of SOFC Materials in Operational Conditions: A Doped Ceria Study. Membranes. 10(7):1-16. https://doi.org/10.3390/membranes10070148S116107Maher, R. C., Duboviks, V., Offer, G. J., Kishimoto, M., Brandon, N. P., & Cohen, L. F. (2013). Raman Spectroscopy of Solid Oxide Fuel Cells: Technique Overview and Application to Carbon Deposition Analysis. Fuel Cells, 13(4), 455-469. doi:10.1002/fuce.201200173Cheng, Z., Wang, J.-H., Choi, Y., Yang, L., Lin, M. C., & Liu, M. (2011). From Ni-YSZ to sulfur-tolerant anode materials for SOFCs: electrochemical behavior, in situ characterization, modeling, and future perspectives. Energy & Environmental Science, 4(11), 4380. doi:10.1039/c1ee01758fLiu, M., Lynch, M. E., Blinn, K., Alamgir, F. M., & Choi, Y. (2011). Rational SOFC material design: new advances and tools. Materials Today, 14(11), 534-546. doi:10.1016/s1369-7021(11)70279-6Maher, R. C., Shearing, P. R., Brightman, E., Brett, D. J. L., Brandon, N. P., & Cohen, L. F. (2015). Reduction Dynamics of Doped Ceria, Nickel Oxide, and Cermet Composites Probed Using In Situ Raman Spectroscopy. Advanced Science, 3(1), 1500146. doi:10.1002/advs.201500146Laguna-Bercero, M. A., & Orera, V. M. (2011). Micro-spectroscopic study of the degradation of scandia and ceria stabilized zirconia electrolytes in solid oxide electrolysis cells. International Journal of Hydrogen Energy, 36(20), 13051-13058. doi:10.1016/j.ijhydene.2011.07.082Brett, D. J. L., Kucernak, A. R., Aguiar, P., Atkins, S. C., Brandon, N. P., Clague, R., … Vesovic, V. (2010). What Happens Inside a Fuel Cell? Developing an Experimental Functional Map of Fuel Cell Performance. ChemPhysChem, 11(13), 2714-2731. doi:10.1002/cphc.201000487Sheppard, N. (1982). Recent developments in the vibrational spectroscopies (infrared, Raman, electron energy loss etc.) as applied to the structural analysis of species chemisorbed on metal surfaces. Journal of Molecular Structure, 80, 163-174. doi:10.1016/0022-2860(82)87225-6Balaguer, M., Solís, C., & Serra, J. M. (2012). Structural–Transport Properties Relationships on Ce1–xLnxO2−δ System (Ln = Gd, La, Tb, Pr, Eu, Er, Yb, Nd) and Effect of Cobalt Addition. The Journal of Physical Chemistry C, 116(14), 7975-7982. doi:10.1021/jp211594dMogensen, M. (2000). Physical, chemical and electrochemical properties of pure and doped ceria. Solid State Ionics, 129(1-4), 63-94. doi:10.1016/s0167-2738(99)00318-5Balaguer, M., García-Fayos, J., Solís, C., & Serra, J. M. (2013). Fast Oxygen Separation Through SO2- and CO2-Stable Dual-Phase Membrane Based on NiFe2O4–Ce0.8Tb0.2O2-δ. Chemistry of Materials, 25(24), 4986-4993. doi:10.1021/cm4034963Degen, T., Sadki, M., Bron, E., König, U., & Nénert, G. (2014). The HighScore suite. Powder Diffraction, 29(S2), S13-S18. doi:10.1017/s0885715614000840Rietveld, H. M. (1969). A profile refinement method for nuclear and magnetic structures. Journal of Applied Crystallography, 2(2), 65-71. doi:10.1107/s0021889869006558Rodríguez-Carvajal, J. (1993). Recent advances in magnetic structure determination by neutron powder diffraction. Physica B: Condensed Matter, 192(1-2), 55-69. doi:10.1016/0921-4526(93)90108-iShannon, R. D. (1976). Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides. Acta Crystallographica Section A, 32(5), 751-767. doi:10.1107/s0567739476001551Taniguchi, T., Watanabe, T., Sugiyama, N., Subramani, A. K., Wagata, H., Matsushita, N., & Yoshimura, M. (2009). Identifying Defects in Ceria-Based Nanocrystals by UV Resonance Raman Spectroscopy. The Journal of Physical Chemistry C, 113(46), 19789-19793. doi:10.1021/jp9049457Weber, W. H., Hass, K. C., & McBride, J. R. (1993). Raman study ofCeO2: Second-order scattering, lattice dynamics, and particle-size effects. Physical Review B, 48(1), 178-185. doi:10.1103/physrevb.48.178Parayanthal, P., & Pollak, F. H. (1984). Raman Scattering in Alloy Semiconductors: «Spatial Correlation» Model. Physical Review Letters, 52(20), 1822-1825. doi:10.1103/physrevlett.52.1822Kosacki, I., Suzuki, T., Anderson, H. U., & Colomban, P. (2002). Raman scattering and lattice defects in nanocrystalline CeO2 thin films. Solid State Ionics, 149(1-2), 99-105. doi:10.1016/s0167-2738(02)00104-2McBride, J. R., Hass, K. C., Poindexter, B. D., & Weber, W. H. (1994). Raman and x‐ray studies of Ce1−xRExO2−y, where RE=La, Pr, Nd, Eu, Gd, and Tb. Journal of Applied Physics, 76(4), 2435-2441. doi:10.1063/1.357593Esther Jeyanthi, C., Siddheswaran, R., Kumar, P., Siva Shankar, V., & Rajarajan, K. (2014). Structural and spectroscopic studies of rare earths doped ceria (RELa,Sc,Yb:CeO2) nanopowders. Ceramics International, 40(6), 8599-8605. doi:10.1016/j.ceramint.2014.01.076Shirbhate, S., Nayyar, R. N., Ojha, P. K., Yadav, A. K., & Acharya, S. (2019). Exploration of Atomic Scale Changes during Oxygen Vacancy Dissociation Mechanism in Nanostructure Co-Doped Ceria: As Electrolytes for IT-SOFC. Journal of The Electrochemical Society, 166(8), F544-F554. doi:10.1149/2.1191908jesArtini, C. (2018). Rare-Earth-Doped Ceria Systems and Their Performance as Solid Electrolytes: A Puzzling Tangle of Structural Issues at the Average and Local Scale. Inorganic Chemistry, 57(21), 13047-13062. doi:10.1021/acs.inorgchem.8b02131Spanier, J. E., Robinson, R. D., Zhang, F., Chan, S.-W., & Herman, I. P. (2001). Size-dependent properties ofCeO2−ynanoparticles as studied by Raman scattering. Physical Review B, 64(24). doi:10.1103/physrevb.64.245407Zhang, F., Chan, S.-W., Spanier, J. E., Apak, E., Jin, Q., Robinson, R. D., & Herman, I. P. (2002). Cerium oxide nanoparticles: Size-selective formation and structure analysis. Applied Physics Letters, 80(1), 127-129. doi:10.1063/1.1430502Suzuki, T., Kosacki, I., Anderson, H. U., & Colomban, P. (2004). Electrical Conductivity and Lattice Defects in Nanocrystalline Cerium Oxide Thin Films. Journal of the American Ceramic Society, 84(9), 2007-2014. doi:10.1111/j.1151-2916.2001.tb00950.xDohčević-Mitrović, Z. D., Šćepanović, M. J., Grujić-Brojčin, M. U., Popović, Z. V., Bošković, S. B., Matović, B. M., … Aldinger, F. (2006). The size and strain effects on the Raman spectra of Ce1−xNdxO2−δ (0≤x≤0.25) nanopowders. Solid State Communications, 137(7), 387-390. doi:10.1016/j.ssc.2005.12.006Balaguer, M., Solís, C., & Serra, J. M. (2011). Study of the Transport Properties of the Mixed Ionic Electronic Conductor Ce1−xTbxO2−δ + Co (x = 0.1, 0.2) and Evaluation As Oxygen-Transport Membrane. Chemistry of Materials, 23(9), 2333-2343. doi:10.1021/cm103581wBalaguer, M., Solís, C., Roitsch, S., & Serra, J. M. (2014). Engineering microstructure and redox properties in the mixed conductor Ce0.9Pr0.1O2−δ+ Co 2 mol%. Dalton Trans., 43(11), 4305-4312. doi:10.1039/c3dt52167bAcharya, S. A., Gaikwad, V. M., Sathe, V., & Kulkarni, S. K. (2014). Influence of gadolinium doping on the structure and defects of ceria under fuel cell operating temperature. Applied Physics Letters, 104(11), 113508. doi:10.1063/1.4869116Zallen, R., & Conwell, E. M. (1979). The effect of temperature on libron frequencies in molecular crystals: Implications for TTF-TCNQ. Solid State Communications, 31(8), 557-561. doi:10.1016/0038-1098(79)90252-7Hart, T. R., Aggarwal, R. L., & Lax, B. (1970). Temperature Dependence of Raman Scattering in Silicon. Physical Review B, 1(2), 638-642. doi:10.1103/physrevb.1.638Lughi, V., & Clarke, D. R. (2007). Temperature dependence of the yttria-stabilized zirconia Raman spectrum. Journal of Applied Physics, 101(5), 053524. doi:10.1063/1.2697347Long, R. Q., Huang, Y. P., & Wan, H. L. (1997). Surface Oxygen Species Over Cerium Oxide and Their Reactivities with Methane and Ethane by Means ofin situConfocal Microprobe Raman Spectroscopy. Journal of Raman Spectroscopy, 28(1), 29-32. doi:10.1002/(sici)1097-4555(199701)28:13.0.co;2-gPushkarev, V. V., Kovalchuk, V. I., & d’ Itri, J. L. (2004). Probing Defect Sites on the CeO2 Surface with Dioxygen. The Journal of Physical Chemistry B, 108(17), 5341-5348. doi:10.1021/jp0311254Weber, A., & McGinnis, E. A. (1960). The Raman spectrum of gaseous oxygen. Journal of Molecular Spectroscopy, 4(1-6), 195-200. doi:10.1016/0022-2852(60)90081-3Hornés, A., Bera, P., Fernández-García, M., Guerrero-Ruiz, A., & Martínez-Arias, A. (2012). Catalytic and redox properties of bimetallic Cu–Ni systems combined with CeO2 or Gd-doped CeO2 for methane oxidation and decomposition. Applied Catalysis B: Environmental, 111-112, 96-105. doi:10.1016/j.apcatb.2011.09.022Duboviks, V., Maher, R. C., Offer, G., Cohen, L. F., & Brandon, N. P. (2013). In-Operando Raman Spectroscopy Study of Passivation Effects on Ni-CGO Electrodes in CO2 Electrolysis Conditions. ECS Transactions, 57(1), 3111-3117. doi:10.1149/05701.3111ecstDuboviks, V., Maher, R. C., Kishimoto, M., Cohen, L. F., Brandon, N. P., & Offer, G. J. (2014). A Raman spectroscopic study of the carbon deposition mechanism on Ni/CGO electrodes during CO/CO2 electrolysis. Phys. Chem. Chem. Phys., 16(26), 13063-13068. doi:10.1039/c4cp01503

Study of Pr and Pr and Co doped La2NiO4+δ as cathodes for La5.5WO11.25-δ based protonic conducting fuel cells

[EN] The mixed ionic-electronic conductor La2NiO4+delta was investigated as potential cathode material for protonic conducting solid oxide fuel cells (PC-SOFCs) based on La5.5WO11.25-delta electrolyte. Firstly the chemical compatibility between cathode and electrolyte phases (La2NiO4+delta and La5.5WO11.25-delta respectively) was studied. Then, the electrochemical properties of this cathode were improved by partially substituting La and/or Ni, specifically La1.5Pr0.5NiO4+delta and La(1.5)Pro(0.5)Nio(0.8)Co(0.2)O(4+delta) were considered. These two doped materials showed improved electrical conductivity and reduced polarization resistance, when tested as cathode in symmetrical cells. In a second step, the microstructure of La(1.5)Pro(0.5)Nio(0.8)Co(0.2)O(4+delta) was optimized by varying the firing temperature of the cathode. The performance of these mixed conductors is limited by medium frequencies associated processes while they show lower polarization resistances (Rp) than conventional composites based on La5.5WO11.25-delta and pure electronic conductors. La(1.5)Pro(0.5)Nio(0.8)Co(0.2)O(4+delta) cathode sintered at 1050 degrees C exhibits the best electrochemical performance on a La5.5WO11.25-delta-based PC-SOFC, achieving Rp = 0.62 Omega cm(2) at 750 degrees C in wet air.Funding from European Union (FP7 Project EFFIPRO - Grant agreement 227560), the Spanish Government (ENE2011-24761, SEV-2012-0267, BES-2012-053180 and CSIC Intramural 200880I093 grants) is kindly acknowledged. The authors thank M. Fabuel for sample preparation.Solis Díaz, C.; Navarrete Algaba, L.; Serra Alfaro, JM. (2013). Study of Pr and Pr and Co doped La2NiO4+δ as cathodes for La5.5WO11.25-δ based protonic conducting fuel cells. Journal of Power Sources. 240:691-697. https://doi.org/10.1016/j.jpowsour.2013.05.055S69169724

Osteogenic effects of simvastatin-loaded mesoporous titania thin films

The use of statins in the field of bone regeneration is under current investigation due to the existing demand for non-toxic anabolic agents capable of enhancing bone formation in cases of substantial loss. Simvastatin, a coenzyme currently prescribed in clinics to inhibit cholesterol biosynthesis, has been proven to promote osteogenic differentiation by stimulating bone formation and inhibiting osteoclasts activity. We present the loading of simvastatin in mesoporous TiO2 thin films toward combining the pro-osteogenic properties of this molecule with the demonstrated bioactivity of titania. TiO2 thin films processing and characterization were carried out, as well as evaluation of MC3T3-E1 pre-osteoblasts viability when directly incubated with different concentrations of simvastatin, followed by the analysis of osteogenic activity promoted by simvastatin upon loading in the thin films. The accessible porosity of 36% quantified on the 95 ± 5 nm thick mesoporous thin films, together with pore diameters of 5.5 nm, necks between pores of 2.8 nm and interpore distances of 12 ± 2 nm allow the loading of the simvastatin molecule, as confirmed by FTIR spectroscopy. Simvastatin was found to promote MC3T3-E1 pre-osteoblasts viability at concentrations ≤0.01 g l−1, with a cytotoxicity threshold of 0.05 g l−1. We additionally found that film loadings with 0.001 g l−1 simvastatin promotes statistically higher MC3T3-E1 pre-osteoblast proliferation whereas a higher concentration of 0.01 g l−1 leads to statistically higher osteogenic activity (ALP synthesis), after 21 days of incubation, as compared to unloaded films. These results demonstrate the potential of simvastatin local administration based on bioactive mesoporous thin films to promote pro-osteogenic properties. By focusing this strategy on the coating of metallic prostheses, the supply of simvastatin to the target tissue can be favored and risks of systemic side effects will be reduced while enhancing the osteointegration of the implants.Fil: Lopez Alvarez, Miriam. Universidad de Vigo; EspañaFil: López Puente, Vanesa. Universidad de Vigo; EspañaFil: Rodriguez Valencia, Cosme. Universidad de Vigo; EspañaFil: Angelome, Paula Cecilia. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Liz Marzan, Luis M. Ikerbasque; EspañaFil: Serra, Julia. Universidad de Vigo; EspañaFil: Pastoriza Santos, Isabel. Universidad de Vigo; EspañaFil: Gonzalez, Pio. Universidad de Vigo; Españ

Vanadium redox flow batteries real-time State of Charge and State of Health estimation under electrolyte imbalance condition

This paper presents a novel observer architecture capable to estimate online the concentrations of the four vanadium species present in a vanadium redox flow battery (VRFB). The proposed architecture comprises three main stages: (1) a high-gain observer, to estimate the output voltage and its derivatives; (2) a dynamic inverter, to obtain a set of concentration candidate solutions; and (3) a static selector, to determine the actual concentrations. The methodology does not rely on the classic assumption of balanced electrolytes, thus significantly widening the application range in comparison with most of the literature previous studies. Furthermore, to perform the estimation, only a single voltage and current measurements are required, which eliminates the need of including complex and costly additional sensors. To validate the proposal, comprehensive simulation tests are conducted. These tests take into account typical side reactions that cause imbalance in VRFB systems, such as vanadium crossover and oxidation. The observer shows a remarkable performance when dealing with these realistic conditions, allowing to estimate with high accuracy and robustness the four vanadium concentrations, the State of Charge and the State of Health with a relative error below 2%.The project that gave rise to these results received the support of a fellowship from ”la Caixa” Foundation (ID 100010434). The fellowship code is LCF/BQ/DI21/11860023. This research was also supported by the Spanish Ministry of Science and Innovation, under the projects MAFALDA (PID2021-126001OB-C31) and MASHED (TED2021-129927B-I00). This work has been supported by the Spanish Ministry of Universities funded by the European Union - NextGenerationEU (2022UPC-MSC-93823).Peer ReviewedPostprint (published version

Viability of using enamel and dentin from bovine origin as a substitute for human counterparts in an intraoral erosion model

This study ascertained whether under dental erosion models that closely mimics the real-life situation enamel and root dentin from bovine origin would be reliable substitutes for human counterparts. Through a 2x2 crossover design, in a first trial, 14 volunteers wore a palatal device containing slabs of bovine and human enamel. Half of the participants ingested (4x daily, for 10 days) orange juice first, crossing over to mineral water, while the remainder received the reverse sequence. In a second trial, volunteers wore devices with slabs of bovine and human root dentin. Except for the duration of each intraoral phase, which lasted 2 rather 10 days, the experiment with root dentin run exactly as for enamel. Dental substrates were analyzed for surface microhardness. Two-way ANOVAs (α=0.05) indicated no difference between the microhardness values recorded for human and bovine enamel (p=0.1350), but bovine root dentin had lower microhardness compared to its human counterpart (p=0.0432). While bovine enamel can reliably substitute its human counterpart in in situ dental erosion models, bovine root dentin does not seem to be a viable alternative to the corresponding human tissue.Este estudo visou avaliar, sob um modelo de erosão dental que se aproxima da realidade clínica, se o esmalte e a dentina radicular bovinos seriam substitutos viáveis aos correspondentes substratos de origem humana. De acordo com um delineamento crossover 2x2, 14 voluntários utilizaram dispositivos palatinos contendo fragmentos de esmalte humano e bovino. Metade dos participantes ingeriu suco de laranja (4x/dia, por 10 dias) e, a seguir, alternou para a ingestão de água mineral, enquanto os demais voluntários receberam a seqüência reversa. Em um segundo experimento, os sujeitos da pesquisa fizeram uso do dispositivo palatino contendo fragmentos de dentina radicular bovina e humana. Exceto pela duração de cada uma das duas fases experimentais (2 ao invés de 10 dias), utilizou-se o mesmo protocolo empregado no estudo em que se comparou o esmalte. Os substratos dentais foram avaliados quanto a sua microdureza superficial. ANOVAs a dois critérios (α=0,05) não indicaram diferença entre os valores de microdureza observados para o esmalte humano e bovino (p=0,1350), porém a dentina radicular apresentou microdureza inferior à humana (p=0,0432). Enquanto o esmalte bovino é um substituto fidedigno do substrato humano em modelos in situ de erosão dental, a dentina radicular bovina não parece ser uma alternativa viável ao tecido humano correspondente.The authors are especially grateful for the valuable participation and cooperation of the volunteers. Thanks are also due to Patricia Marchi, for her technical assistance, and to the Ethylene Oxide Sterilization Center of the Clinical Hospital of the School of Medicine of Ribeirão Preto (USP), for sterilizing the dental slabs. The State of São Paulo Research Foundation (FAPESP, grant #05/01515-8) is acknowledged for providing financial assistance in the form of a scholarship to the first author. This research was partially funded by a grant from the First Projects Program (MCT/CNPq-FAPESP, grant #06/60356-0)

Présentation

Bien que le bilinguisme soit en quelque sorte l’aboutissement naturel de l’acquisition d’une langue seconde, ces deux champs de recherche sont trop souvent restés confinés dans une ignorance réciproque tout à fait regrettable. Il est vrai que la recherche sur l’acquisition s’est longtemps cantonnée à l’étude de situations scolaires, et que, dans ce cadre, la langue étrangère est conçue traditionnellement comme un objet d’appropriation - statut symbolisé d’ailleurs par le terme de langue-cible..

Electrochemical properties of composite fuel cell cathodes for La5.5WO12−δ proton conducting electrolytes

[EN] New composite cathodes for proton conducting solid oxide fuel cells (PC-SOFCs) based on the novel La5.5WO12-delta (LWO) electrolyte have been developed. First the applicability of LWO as a protonic electrolyte has been proved by recording the OCV in a Pt/LWO/Pt cell as a function of the temperature, matching the expected Nernst voltage. In order to improve the electrode performance on LWO PC-SOFCs, composite cathodes have been prepared by mixing the La0.8Sr0.2MnO3-delta (LSM) electronic phase with the LWO protonic phase. The ceramic-ceramic (cer-cer) composites have been electrochemically studied as cathodes on LWO dense electrolytes in symmetrical cells. Different ratios of both phases and two different electrode sintering temperatures (1050 and 1150 degrees C) have been studied. Electrochemical impedance spectroscopy (EIS) analysis has been carried out in the temperature range 700-900 degrees C under moist (2.5% H2O) atmospheres. Different oxygen partial pressures (pO(2)) have been employed in order to characterize the processes (surface reaction and charge transport) taking place at the composite cathode. A substantial improvement in the cathode performance has been attained by the addition of the LWO protonic phase into the LSM electronic material. From the electrochemical analysis it can be inferred that electrode enhancement is principally ascribed to the increase in the three-phase-boundary length, which enables electrochemical reactions to occur along the thickness of the electrode.Funding from European Union (FP7 Project EFFIPRO - Grant Agreement 227560), the Spanish Government (ENE2011-24761 and CSIC Intramural 200880I093 grants) is kindly acknowledged. The authors thank Dr M. Ivanova and Dr D. Sebold (Forschungszentrum Julich, IEK-1) for sample preparation for microscopy analysis, and Mrs M. Fabuel and Dr V. B. Vert for assistance in electrochemical tests.Solis Díaz, C.; Navarrete Algaba, L.; Roitsch, S.; Serra Alfaro, JM. (2012). Electrochemical properties of composite fuel cell cathodes for La5.5WO12−δ proton conducting electrolytes. Journal of Materials Chemistry. 22(31):16051-16059. https://doi.org/10.1039/c2jm32061d1605116059223